解答
化简 −0.14log2(0.14)+(−0.86)log2(0.86)
解答
−log2(25430.86⋅70.14)+1
+1
十进制
0.58423…求解步骤
−0.14log2(0.14)+(−0.86)log2(0.86)
−0.14log2(0.14)=−0.14log2(507)
log2(0.86)=log2(5043)
=−0.14log2(507)−0.86log2(5043)
−0.14log2(507)=−log2((507)0.14)
−0.86log2(5043)=−log2((5043)0.86)
=−log2((507)0.14)−log2((5043)0.86)
使用对数计算法则: loga(x)+loga(y)=loga(xy)−log2((5043)0.86)−log2((507)0.14)=log2((5043)0.86(507)0.14)=−log2((5043)0.86(507)0.14)
化简 (5043)0.86(507)0.14:50430.86⋅70.14
=−log2(50430.86⋅70.14)
使用对数计算法则: loga(yx)=loga(x)−loga(y)log2(50430.86⋅70.14)=log2(430.86⋅70.14)−log2(50)=−(log2(430.86⋅70.14)−log2(50))
log2(430.86⋅70.14)=0.86log2(43)+0.14log2(7)
=−((0.86log2(43)+0.14log2(7))−log2(50))
使用法则: (a)=a(0.86log2(43)+0.14log2(7))=0.86log2(43)+0.14log2(7)=−(0.86log2(43)+0.14log2(7)−log2(50))
log2(50)=1+2log2(5)
=−(0.86log2(43)+0.14log2(7)−(1+2log2(5)))
使用分配律: −(a+b)=−a−b−(1+2log2(5))=−1−2log2(5)=−(0.86log2(43)+0.14log2(7)−1−2log2(5))
0.86log2(43)=log2(430.86)
0.14log2(7)=log2(70.14)
−2log2(5)=−log2(52)
=−(log2(430.86)+log2(70.14)−1−log2(52))
log2(430.86)+log2(70.14)−log2(52)=log2(25430.86⋅70.14)
=−(log2(25430.86⋅70.14)−1)
使用分配律: −(a−b)=−a+b−(log2(25430.86⋅70.14)−1)=−log2(25430.86⋅70.14)+1=−log2(25430.86⋅70.14)+1